Geriatric depression is rarely found without at least some medical co- morbidity and/or impatient in physical functioning. Not only do these conditions complicate the study of geriatric depression, but evidence from the Developing CRC suggests that they are important indicators of heterogeneity in late life mood disorders and contribute to their outcomes; for example in depressed CRC subjects, medical burden predicts chronicity of depression and delayed recovery is associated with increased mortality. The Medical Core is newly added to the CRC and developed from collaborative relationships between investigators in the Departments of Psychiatry and Internal Medicine at Cornell. Addition of the Medical Core uniquely contributes to the CRC's investigation of heterogeneity of late life mood disorders by rigorous and extensive study of medical illness, functional impairment and depression course and outcome. The Medical Core expands the CRC's resource by providing: 1. funded medical investigators with extensive experience conducting longitudinal studies of co-morbidity in medical setting patients and having central roles in the CRC; 2. access to a large population of elderly medical patients accustomed to receiving care in a research environment; 3. training and supervision in the administration of carefully selected instruments to assess longitudinal variation in medical morbidity and functional performance; (4) investigations of depression in post-operative depression in subjects enrolled in funded longitudinal studies of coronary bypass surgery and hip fracture repair. The Medical Core will work with the Clinical Core in screening and recruiting elderly patients from primary care settings for assessments and longitudinal follow-up, including subjects with major depression (N=50), minor depression (N=50) and non-depressed. These patients will contribute to the overall CRC database, yielding a sample of depressed elderly subjects ranging widely in severity and type of medical co-morbidity and functional status, and followed longitudinally with extensive clinical, neuropsychological and psychosocial ratings. As part of its mission, the Medical Core will take advantage of these data to test cross-core hypotheses concerning the reciprocal relationships of depression and medical illness over time.